Files
website/content/zh-cn/docs/tasks/administer-cluster/guaranteed-scheduling-critical-addon-pods.md
Qiming Teng c52818c03d Switch language name 'zh' to 'zh-cn'
This is the first step to rename 'zh' to 'zh-cn'. There are several reasons why we rename the language name.

- The upstream docsy theme changed the language name, leading to many warnings during site build;
  The side-effect is that the i18n strings are no longer working.
- We believe renaming the language is the right thing to do, because this move can make room for other variants of Chinese language, such as 'zh-tw', 'zh-sg' etc.

There would be several follow-ups to this PR, such as fixing the intra-site links, adding redirects etc.

We will lock up changes to zh/zh-cn pages for the moment, until this one gets in.

This PR is based on commit cdad0a7342.
2022-06-10 22:33:41 +08:00

2.4 KiB

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关键插件 Pod 的调度保证 concept

Kubernetes 核心组件(如 API 服务器、调度器、控制器管理器)在控制平面节点上运行。 但是插件必须在常规集群节点上运行。 其中一些插件对于功能完备的集群至关重要,例如 Heapster、DNS 和 UI。 如果关键插件被逐出(手动或作为升级等其他操作的副作用)或者变成挂起状态,集群可能会停止正常工作。 关键插件进入挂起状态的例子有:集群利用率过高;被逐出的关键插件 Pod 释放了空间,但该空间被之前悬决的 Pod 占用;由于其它原因导致节点上可用资源的总量发生变化。

注意,把某个 Pod 标记为关键 Pod 并不意味着完全避免该 Pod 被逐出;它只能防止该 Pod 变成永久不可用。 被标记为关键性的静态 Pod 不会被逐出。但是,被标记为关键性的非静态 Pod 总是会被重新调度。

标记关键 Pod

要将 Pod 标记为关键性(critical),设置 Pod 的 priorityClassName 为 system-cluster-critical 或者 system-node-criticalsystem-node-critical 是最高级别的可用性优先级,甚至比 system-cluster-critical 更高。